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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
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 * GPL Classpath Exception:
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package com.sun.mail.util;

import java.lang.reflect.*;
import java.security.*;

import javax.mail.internet.MimePart;

/**
 * General MIME-related utility methods.
 * 
 * @author Bill Shannon
 * @since JavaMail 1.4.4
 */
public class MimeUtil {

	private static final Method cleanContentType;

	static {
		Method meth = null;
		try {
			String cth = System.getProperty("mail.mime.contenttypehandler");
			if (cth != null) {
				ClassLoader cl = getContextClassLoader();
				Class clsHandler = null;
				if (cl != null) {
					try {
						clsHandler = Class.forName(cth, false, cl);
					} catch (ClassNotFoundException cex) {
					}
				}
				if (clsHandler == null)
					clsHandler = Class.forName(cth);
				meth = clsHandler.getMethod("cleanContentType", new Class[] { MimePart.class, String.class });
			}
		} catch (ClassNotFoundException ex) {
			// ignore it
		} catch (NoSuchMethodException ex) {
			// ignore it
		} catch (RuntimeException ex) {
			// ignore it
		} finally {
			cleanContentType = meth;
		}
	}

	// No one should instantiate this class.
	private MimeUtil() {
	}

	/**
	 * If a Content-Type handler has been specified,
	 * call it to clean up the Content-Type value.
	 */
	public static String cleanContentType(MimePart mp, String contentType) {
		if (cleanContentType != null) {
			try {
				return (String) cleanContentType.invoke(null, new Object[] { mp, contentType });
			} catch (Exception ex) {
				return contentType;
			}
		} else
			return contentType;
	}

	/**
	 * Convenience method to get our context class loader.
	 * Assert any privileges we might have and then call the
	 * Thread.getContextClassLoader method.
	 */
	private static ClassLoader getContextClassLoader() {
		return (ClassLoader) AccessController.doPrivileged(new PrivilegedAction() {
			public Object run() {
				ClassLoader cl = null;
				try {
					cl = Thread.currentThread().getContextClassLoader();
				} catch (SecurityException ex) {
				}
				return cl;
			}
		});
	}
}
